The invention relates to metallurgy, and more particularly, to titanium-based alloys intended for production of rods, fasteners and other parts for aeronautical engineering.
Titanium-based alloy of the following composition, % by weight: aluminum 2-6; molybdenum 69; vanadium 1-3; chromium 0.5-2.0; iron 0-1.5; titanium being the balance is known (USSR Inventor""s certificate #180351, C22C 14/00, 1966).
The above said alloy was suggested for production of forgings and stampings applicable to highly stressed structural parts. Significant disadvantage of the said alloy is its tendency to formation of high-melting inclusions in the process of ingot casting due to high content of such high-melting element as molybdenum ( greater than 6%). Occurrence of such inclusions in highly stressed elements leads to destruction of these parts in operation.
The most close to the proposed alloy in terms of its technical essence is titanium-based alloy of the following composition, % by weight:aluminum 4.0-6.3; vanadium 4.0-5.0; molybdenum 1.5-2.5; chromium 0.8-1.4; iron 0.4-0.8; zirconium 0.01-0.08; carbon 0.01-0.25; oxygen 0.03-0.25; titanium being the balance (USSR Inventor""s Certificate #555161, C22C 14/00, 1977).
This alloy possesses high strength characteristics, good level of plasticity, it can be easily rolled into rod and sheet, it is good welded and does not show tendency to form high-melting inclusions. Among drawbacks of this alloy impossibility of its cold volume stamping due to insufficient level of such indicator of technological plasticity in hardened condition as degree of cold upsetting ( less than 60%) should be mentioned.
Besides, on this alloy in the process of thermal enforcement high level of strength ("sgr"Bxe2x89xa71400 Mpa) can be reached only with small cross-sections, up to 25 mm.
An object of the present invention is to increase the alloy ability to cold volume deforming (upsetting degree xe2x89xa775%), and to attain possibility of thermal enforcement to the high level of strength ("sgr"Bxe2x89xa71400 Mpa).
Solution of the problem is ensured by titanium-based alloy containing aluminum, vanadium, molybdenum, chromium, iron, zirconium, carbon, oxygen, wherein according to the invention components are contained in the following proportion, % by mass:
Regulation of aluminum and chromium content in the claimed alloy composition ensures high ability of the alloy to volume deforming in cold condition (it is easily rolled into rods), absence of tendency to high-melting inclusion formation and possibility of the alloy enforcement by thermal methods with obtaining sufficient level of strength and plasticity characteristics.
When aluminum and chromium contents are lower than minimal values of the claimed range the alloys strength after thermal enforcement decreases ("sgr"B less than 1400 Mpa), i.e. the preset object is not attained.
When aluminum and chromium contents are higher than the maximal claimed limit plasticity of the alloy drops (xcex4 less than 8%, "psgr" less than 40%) at the high level of strength ("sgr"Bxe2x89xa71400 Mpa).